Twin-gate type turnstiles are known in the art, for example, such form of turnstile being described in U.S. Pat. 2,258,896. Such type of turnstile includes two turnstile rotors which rotate between opposite end barriers and a central barrier to permit two avenues of ingress or egress through the turnstile. The spacing of the axes of rotation of the two rotors is such that during the course of their rotation there is a common region in which the arms of the respective rotors overlap and pass through each other as well as through the fixed arms of the central barrier. The central barrier described in said patent and which is commonly employed in the art, is provided by two vertically spaced rows of fixed arms extending between an opposed pair of posts with the arms extending in a widening course from the posts to a maximum widening on an imaginary line extending between the two rotor axes. The arms of the two fixed rows of arms face each other and the terminal lengths of these fixed arms, that is the length sections adjacent the fixed posts follow a relatively straight line course. In the turnstile type disclosed in said patent, the overall plan outline of the central barrier is in the shape of a diamond. This results in the crossing of the fixed barrier arms by the arms of the rotors at or near the ends or extremes of the fixed barrier arms, that is at locations close to the fixed posts. As a consequence, it is possible for a person walking through the turnstile to follow the rotor arms of one row right up to the time they pass through the fixed barrier arms so that the next row of arms on the rotor can arrive at a position in which they sufficiently reduce the opening or exit space between the tip ends of the arm of said next row and the barrier to inhibit or prevent the person egressing the unit. Due to the generally unidirectional rotational operation of the rotor, it thus would become difficult, if not virtually impossible, for the user to work his way out from the entrapment. Furthermore, the spacing of the arms in the two rows of fixed arms in the turnstile disclosed in said patent is such that the arms of one row are in planar alignment with the arms of the other row, and the rotating arms of the two rotors intervene successively vertically spaced ones of the fixed arm pairs. This means that very little clearance space exists between the fixed arms and the arms of the rotors so it is possible for a user during passage through the unit to catch his hand or an article such as a purse, between a rotor arm or the barrier element arm.